Sonic.EXE is extremely similar to Classic Sonic, but with notable differences. His fur is darker, and his arms seem to be "softer", and he smiles abnormally with his mouth being totally dark. The main characteristic of .EXE is his black eyes with small reddish glowing pupils, and his eye sockets secrete slightly pink blood from his lower eyelids, resulting in a permanent mark on his face. Occasionally, Sonic.EXE is depicted being slimmer or flatter to differentiate it from regular Sonic.